Field of the Invention
The present invention relates to apparatus and methods for sorting day-old chicks by sex as determined by video imaging and digital image analysis (computer vision) and having distinctive features including lighting and light wavelengths to enhance imaging of distinguishing wing feather characteristics; camera placement, field of view, depth of field to provide an appropriate xe2x80x9cfield volumexe2x80x9d in which to capture necessary images; physically presenting chick wings to the camera with the xe2x80x9cfield volumexe2x80x9d; and software to rapidly analyze digital images and trigger sorting mechanisms. Features such as singulation, conveying, sorting, and digital imaging equipment may utilize off-the-shelf components.
Sex separation of baby chicks is still mostly done by hand as is discussed by D. S. Warren in xe2x80x9cDistinguishing Sex of Chicks at Hatcheryxe2x80x9d,Agricultural Experimental Station Bulletin 307, Kansas State college of Agricultural and Applied Science, Manhattan, Kans. (1942). Typically workers are positioned around chick sexing tables to observe and sort the males from the females by differences in chick wing feathers. For typical operations hatching 250,000 to 500,000 baby chicks a day, a crew of about ten to thirty people must be involved for the chick sexing. Checking a large number of chicks each day is very labor intensive and the work is tedious, requires special talent and demands tolerance to monotony. Other examples including related operations can be found in U.S. Pat. Nos. 3,994,292, 3,570,487, 3,704,688, and 3,777,752.
There are many advantages of chick sexing in the broiler industry. Because of the growth characteristics of male and female chickens, males tend to grow faster and larger at given conditions. Male broilers fed for an extra couple of weeks can grow to 6 or 7 pounds. For the same time, female birds have a slower growing rate with less weight gain. Raising male and female chickens separately has the advantages of:
1). Enhanced feeding efficiency: By growing and harvesting male and female broiler chickens differently, it enables the better management for optimum returns.
2). Improved de-bone meat production: Harvesting deboned meats by using large male broilers provided increased benefits at the marketplace.
3). Processing line efficiency: With reduced variation of large and small bird sizes, the equipment may be more precisely adjusted to achieve greater performance. The equipment can handle more uniform sized birds for enhanced yield, efficiency and productivity.
Technologies using machine vision have great potential to enable automated chick sex sorting operations. By using digital video cameras, automated mechanics, and computer image processing systems, the automated system will inspect chicks at high speed. The machine vision sorting can further enhance chick sexing practice with additional advantages of:
1). Higher throughput: With a speed of 10 chicks per second, the machine can finish the job in a timely manner and eliminate any bottlenecks of sexing operations.
2). Labor savings and cost benefits: Labor cost alone can exceed 0.6 cents per chick so that a substantial savings is possible for a 250,000 chick per day operation. Machine cost of something over $100,000 will have a very short payback.
3). Fewer human errors: The machine has the advantage of accuracy and consistency with reduced errors. There will be three sorting paths: male, female, and rework (for cases where the system receives too little information to process an individual chick). In case of a few very difficult chicks, human inspection could be used with minimal labor involvement.
To either present chick sexing practice or machine vision sexing technology, there are significant advantages in the competitive marketplace if such methods can be further automated, not only in gained feed and production efficiencies, but also in cost savings.
Various devices to further automate sexing have been proposed previously. For example, M. D. Evans, in xe2x80x9cFeather Sexing of Boiler Chicks by Machine Visionxe2x80x9d ASAE paper no. 903008, ASAE, St. Joseph, Mich. (1989), discusses such equipment. Also, P. T. Jones, S. A. Shearer and R. S. Gates in xe2x80x9cEdge Extraction for Feather Sexing Poultry Chicks,xe2x80x9d Transcript of ASAE 3492): 635-640 (1991) discuss such equipment. U.S. Pat. No. 4,417,663 to K. Suzuki in 1983, and entitled xe2x80x9cApparatus for Determining the Sex of a Chickxe2x80x9d also discusses similar equipment. However, the known art fails to teach a reliable, fast method for automatic chick sexing. Thus, a need exists for an improved, more automated process for chick sexing.
The invention addresses the above referenced need in the art. In particular, the invention provides an improved method for automatic chick sexing.
Under regular lighting, the color intensity of down and feather of baby chicks are essentially the same and it is difficult to separate the feathers in the image. However, by using UV light, our new optical system significantly enhanced the feathers by suppressing the downs in images. It produced clear feather signals for subsequent identification and allocation of feathers in the image. The strong signal ratio between feather and down made it much easier for the consequent image processing without sophisticated noise removing process as proposed by Jones et al. (1991) and Evans (1989). (Because of the good contrast, the feather image segments could be obtained through thresholding with any value from 200 to 230 on the 255 maximum intensity scale. For consistency, a threshold value of 200 was used for all images throughout the experiment.)
Important features of the invention include a video camera, special lighting, an image processing system and a computer for analysis. The combination facilitates more efficient automatic chick sexing than previous devices.
The digital video camera captures a clear image of chick wings using selected light wavelengths (including long UV wavelengths). Special lighting architecture provides maximum illumination enhancement and feature extraction for the camera and the pattern recognition software. Lighting wavelength and camera wavelength sensitivity have been shown to have critical effects on image quality and feature extraction. The digital image processing system processes signals from the camera and it makes instantaneous image analysis. The computer system hosts the digital imaging system and it executes the decisions made by the digital image processing system.
Previously known and herein disclosed image processing algorithms for identification, feature extraction, and pattern recognition of chick sexes by wing feathers, include specialized software programs. They include high speed blur-less imaging of chick presented by mechanical system as well as software algorithms that identify wing tips and extract male and female features. Other software includes fast pattern recognition algorithms to distinguish male and female chicks at an accuracy of up to 95%or higher at up to 12 chicks /sec. These software controlled electronics can also control the chick sorting mechanism.
Thus, a principal object of the present invention is to provide an improved method for chick sexing.
A related object is to provide a safe and inexpensive process that automates chick sexing.
Another object is to provide a chick sexing method that does not harm the chicks.
Yet another object of the present invention is to provide increased reliability in chick sexing operations.